.gxl-table-header-cell {
    margin: 0px -1px -1px -1px;
    position: relative;
    display: inline-block;
    border:1px transparent solid;
    border-image:linear-gradient(to top,#999,transparent) 1 10;
    border-bottom-color:#999;
    font-size: 0.8rem;
    text-align: center;
    line-height: 2rem;
    background-color: #cfcfcf;
  }